You should consider stepping back and spending 25 or 50% time mentoring instead of coding. But what I've found is that it's REALLY hard to do something 20% with

You should consider stepping back and spending 25 or 50% time mentoring instead of coding. But what I've found is that it's REALLY hard to do something 20% without doing it 100%, so perhaps a few weeks (months) of NO coding, then starting to code again.